This relates generally to electronic devices and, more particularly, to displays for electronic devices.
Electronic devices such as cellular telephones, computers, and media players often contain displays. For example, electronic devices often include backlit displays such as backlit liquid crystal displays.
Backlit displays generally include a light distribution layer called a light guide plate. The light guide plate is typically formed from a rectangular sheet of clear plastic that has been injection molded, extruded, or die cut from a sheet of plastic. Light from an array of light-emitting diodes may be launched into the edge of the light guide plate. The light guide plate distributes light across the back of a display panel by total internal reflection. Light that exits the planar upper surface of the light guide plate serves as backlight for the display panel.
In relatively large electronic devices such as televisions, the light guide plate can have a thickness that allows reflective material such as reflective tape to be attached to edges of the light guide plate that prevents light from the light guide plate from leaking into undesired areas of the device.
However, it can be challenging to add reflective structures such as tape to relatively thinner light guide plates for compact devices such as laptop computers, tablet computers, and cell phones. For example, the housing of an electronic device can be adjusted to accommodate additional reflective structures or to accommodate a larger light guide plate in which edges of the light guide plate that are prone to light leakage are embedded within additional space within the housing. However, this can lead to undesirable enlargement of the size and weight of the housing and unappealing device aesthetics.
It would therefore be desirable to be able to provide improved display backlight structures such as improved light guide plates for display backlights.